Cylinder ridge reamer



1 Oct. 26, 1948. B R AN 2,452,095

CYLINDER RIDGE REAMER Filed June 5, 1946 2 Sheets-Sheet 1 Ja a a c". 7 J 1 a ii; 1? I34 U? if! k W:

4 H [(HHUH III/Ill I L1 1/617 {M MAW Oct. 26, 1948. N 2,452,095

CYLINDER RIDGE 'REAMER Filed June 5, 1946 2 Sheets-Sheet 2 Patented Oct. 26, 1948 CYLINDER RIDGEREAMER Herbert A. Berkman, Chicago, Ill., assignor to Zim Manufacturing Company, a corporation of Illinois Application June 5, 1946, Serial'No. 674,475

8 Claims.

The present invention relates to that type of small machine or tool for dressing cylinders of internal combustion engines, which is adapted to be anchored in fixed relation to a cylinder in such a position that a rotatable cutting element may operate to remove metal from the cylinder wall; and it has for its object a simple and novel improvement to enable the cutting element to travel lengthwise of the cylinder in addition to rotating around the cylinder axis.

Devices of the general type to which my improvement may be applied are disclosed in my prior Patents Nos. 2,136,350 and 2,270,854; and, viewed in one of its aspects, the present invention may be said to have for its object to permit the cutting element thereof to travel in the direction of the length of the cylinder without requiring the main rotating parts of the device to do likewise.

The various features of novelty whereby the present invention is characterized will hereinafter be pointed out with particularity in the claims, but, for a full understanding of the invention and of its objects and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawings, wherein:

Figure 1 is a top plan View of a ridge reamer embodying the present invention positioned in a cylinder to be reamed, only a fragment of the cylinder being shown; Fig. 2 is a side elevational view of the device shown in Fig. l, the cylinder being in section; Fig, 3 is a view similar to Fig. 2, with the reamer turned ninety degrees from the position it occupies in Fig. 2; Fig. 4 is a section on line 4-4 of Fig. 2; Fig. 5 is a section on line 5-5 of Fig. 2; Fig. 6 is a section on line 60 of Fig. 1; Fig. 7 is a front view of the swinging arm on which the cutting blade is'carried; Fig. 8 is a perspective view of the sliding block on which the cutting blade is mounted; Fig, 9 is a perspective view of the cutting blade; and Fig. 10 is a side view of the upper end of that shoe, of the group of shoes by which the device is fixed in the cylinder, that carries the pin which causes automatic feeding movements of the blade in the lengthwise direction.

In the drawings I have illustrated my improvement applied to the tool disclosed in my aforesaid patents, namely: a disc or table I having a tubular stem 2; along bolt 3 extending through the stem and disc into screwthreaded engagement with a spider 4 below the disc; fiat shoes 5 distributed about and cooperating with the spider'so as to be spaced apart by the latter to clamp the disc firmly within an engine cylinder A; a second disc 0 almost as large as disc I and.

having a hub! of polygonal exterior surrounding stem 2 and prevented from moving up by a headed screw 8 carried by'bolt 3; a plate l0 overlying and slidable on the disc 6 and adjustably secured thereto by a screw H extending through a long slot l2 in the plate and int-o the disc; a cylindrical, rod-like handle I3, rising from plate l0 for turning this plate and the disc 6; and a sturdy arm l4 overlying plate I0, connected thereto by a hinge pin l5, and carrying the cutter blade. As in Patent 2,270,854, a spring It, behind the free end of arm It, tends constantly to swing that end outwardly, whereas a cam device ll lies on the front or outer side of the arm to press it back against the resistance of the spring.

Arm M has a part l8, about midway between its ends, in the form of a heavy, square post or column rising .a substantial distance above the upper face of the arm. In the outer side of mem-' flat cutter blade 2| which, when placed side by side constitute a unit that is a slidable fit in the guideway. The block constitutes the immediate support for the blade which is preferably pivoted thereto. In the arrangement shown, the block has a pin 22 projecting from one side thereof and adapted to be received in a complementary hole 23 in the blade; this arrangement permitting the block and blade to be separated upon removal from the guideway, but holding them securely in hinged relation to each other while they are together in the guideway. The actual cutting section 24 of the blade is at one end of the outer *long edge of the blade, the remainder of said edge being blunt, as at 25, Because the blade is preferably quite thin, adequate bluntness of the edge below the cutting area may conveniently be achieved by binding a narrow marginal portion of the blade laterally to create a little flange or.

lip.

Extending through and rotatably supported in the post or column I 8,from top to bottom, directly behind the guideway, is a shaft 26. A long section 21 of this shaft, extending up from a point near the lower end,'is enlarged in diameter and is screwthreaded, the screw thread being exposed in'the bottom of the groove which forms the guideway. The blade-supporting block 20 has along its rear edge a series of teeth 28 or fragments of a helical screw thread that is complementary to the thread on the shaft; these teeth meshing with the thread on the shaft when the block and the blade are inserted in the guideway. The teeth on the block do not extend across the entire width of the rear edge of the block, but only a short distance inward from the face of the block against which the blade lies. This provides a shoulder 29 on the block that is in sliding engagement with a ledge 30 in the guideway beside the screw and avoids the transmission of inward thrusts of the block against the screw shaft.

A spring-pressed ball 3| is mounted in the post or column 18 so as to project into the guideway and engage with the side of the blade-supporting block opposite that on Which the blade is located. When the block and the blade are inserted in the guideway, the ball is pushed back a little so as thereafter to be able to exert a yielding pressure which forces the block against the blade and the blade against the side of the guideway.

A nut 32 on the upper end of shaft 26, above the post or column, holds the shaft up, whereas a star wheel 34 fixed to the lower end of the shaft, below the post or column, prevents the shaft from I moving upward.

Means are provided to turn the star wheel step by step as the disc 6, with the parts mounted thereon, is rotated in the usual way. This means,

in the arrangement shown, consists of a pin 35 fixed to and rising from the upper end of one of the shoes the pin passing through a radial slot 36 in stationary table or disc I and into the path followed by the star wheel as the latter revolves with disc 6. With this arrangement, the star wheel is turned through one step about its own axis for each revolution about the axis of the tool as a whole. Consequently, if there are six points or arms on the star wheel, as shown, the screw shaft will turn through one sixth of a revolution about its own axis while the cutter blade makes one complete circuit of the interior of the cylinder. By placing the pin 35 on One of the shoes 5 instead of on the disc or table I, it is automatically adjustable in the radial direction for cylinders of different diameters, to maintain the same relative position between the pin and the star Wheel regardless of the diameter of the cylinder; this being due to the fact that the sliding plate I B and each shoe 5 must be shifted to the same extent to adapt the tool to one size. of cylinder after it has been used in reaming a cylinder of a different size.

In using the improved tool, a blade and its supporting block having been inserted in the guideway, it is placed in a cylinder A to be reamed and is fixed therein with the blade inwardly from or below the ridge to be cut away. The arm I4 is held back by the cam device l1 until the tool has been installed and the sliding plate Ill adjusted to bring the blade near the cylinder wall. Whereupon the cam device is turned to release arm l4 and permit spring 16 to force the blade against the cylinder wall, as shown inFigs. 3 and 6, with any desired degree of pressure. The blunt portion of the blade extends in both directions from the pivotal axis of the blade and in line with the outermost point of the cutting edge. Consequently the radial pressure of the blade is transmitted to the cylinder wall through the blunt edge of the blade and no cutting of the wall inwardly or downwnardly from the ridge can occur. When the rotatable upper part of the tool is turned,t-he screw shaft is also turned step by step about. its own axis, so as gradually to feed the blade and its supporting block lengthwise of the cylinder; the blade cutting into the under side or edge of the ridge to be reamed. The rocking motion which the blade is free to make, within limits, insures that the contour of the reamed area will conform exactly to that of the adjacent portion of the cylinder wall, because the blade adjusts itself automatically tocompensate for any variations in the radii of a cylinder at different points in the circle as the blade moves around the cylinder.

It will be seen that the plane of the blade is approximately radial to the axis of the tool and to that of the cylinder, so that the thrust thereof is at right angles to its pivot pin and is transmitted from the latter, through block 20, to the spring pressed supporting arm. Therefore no stresses are imposed on the screw shaft except those incident to moving along the blade-supporting block made heavier, as it were, by the resistance encountered by the blade in doing its work. Therefore a relatively light shaft, supported at both ends, as shown, gives good service.

It will also be seen that by mounting the actual cutting element on a little supporting block it is no more difficult or costly to replace a blade than in an ordinary tool wherein the cutter simply revolves about the axis of the cylinder; the block itself being a permanent part of the tool with respect to which wear is very slight.

While I have illustrated and described with particularity only a single preferred form of my invention, I do not desire to be limited to the exact details thus illustrated and described, but intend to cover all forms and arrangements that come within the definitions of my invention constituting the appended claims.

I claim:

1. In a cylinder reamer, a device having thereon a rotatable member, means to secure said device in an engine cylinder at a substantial distance from a ridge to be reamed, an element on said rotatable member having a longitudinal guideway in position to face the cylinder wall and be near and parallel thereto, a block narrower than the guideway slidable in and lengthwise of the latter, a cutter blade lying flat beside the block in the guideway, the blade being pivoted to the block for rocking movements in an approximately radial plane and projecting outwardly from said block, and means to cause the block to move lengthwise of the guide-way when the rotatable member is turned.

2. In a cylinder reamer, a, device having thereon a rotatable member, means to secure said device in an engine cylinder at a substantial distance from a ridge to be reamed, an element on said rotatable member having a longitudinal guideway in position to face the cylinder wall and be near and parallel thereto, a block narrower than the guideway slidable in and lengthwise of the latter, said block having a short pin projecting from one side, a cutter blade lying flat beside the block in the guideway and containing a hole in which the pin is seated, whereby the blade is pivoted for rocking movements in an approximately radial plane and projecting outwardly from said block, and means to cause the block to move lengthwise of the guideway when the rotatable member is turned.

3. In a cylinder reamer, a device having thereon a rotatable member, means to secure said device in an engine cylinder at a substantial distance from a ridge to be reamed, an element on said rotatable member having a longitudinal guideway in position to face the cylinder wall and be near and parallel thereto, a block narrower than the guideway slidable lengthwise in the latter, a cutter blade lying flat beside the block in the guideway, the blade being pivoted to the block for rocking movements in an approximately radial plane and projecting outwardly from said block, a device at one side of the guideway that engages the block and yieldingly presses it and the blade against the opposite side of the guideway, and means to cause the block to move lengthwise of the guideway when the rotatable member is turned.

4. In a cylinder reamer, a device having thereon a rotatable member, means to secure said device in an engine cylinder at a substantial distance from a ridge to be reamed, an element on said rotatable member having a longitudinal guideway in position to face the cylinder wall and be near and parallel thereto, a block narrower than the guideway slidable in and lengthwise of the latter, a cutter blade lying flat beside the block in the guideway, the blade being pivoted to the block for rocking movements in an approximately radial plane and projecting outwardly from said block, a screw shaft in and extending lengthwise of the guideway behind the block, said block having thereon elements engaging the threads on the near side of the shaft only to cause the block to move lengthwise of the guideway when the near side of the shaft only is turned, and means to turn the near side of the shaft only automatically when said member is rotated.

5. A reamer as set forth in claim 4, wherein the guideway contains a longitudinal bearing surface behind the slidable block to take inward thrusts of the block and prevent such thrusts from being imposed on the screw shaft 6. A reamer as set forth in claim 4, wherein there are bearings for both ends of the screw shaft on the element along which the block slides.

7. In a cylinder reamer, a device having thereon a rotatable member, means to secure said device in an engine cylinder at a substantial distance from a ridge to be reamed, an element on said rotatable member having a long, outwardly facing peripheral channel arranged parallel to the axis of the device, a screw shaft rotatably mounted in the channel so as to extend lengthwise of and along the bottom of the latter, a ledge in the bottom of the channel at one side of the screw, a block resting against said ledge and slidable thereon lengthwise or the channel, the block being narrower than the channel, a cutter lying flat against one side of the block and connected thereto so as to protrude beyond the outer edge thereof, the combined thicknesses of the block and the cutter being such as to make the block and cutter assembly a sliding fit in the channel, said block having thereon elements to cooperate with the threads on the near side of the shaft only, means for turning said rotatable member, and means to cause the screw shaft to be turned and move the block and cutter along the channel when said rotatable member is turned.

8. In a cylinder reamer, a device having thereon a rotatable member, expansible means to secure said device in engine cylinders of different diameters, an element mounted on said rotatable member for adjustment radially of the axis of rotation, said member containing a longitudinal guideway in position to face the cylinder wall and be near and parallel thereto, a cutter unit mounted in the guideway and slidable in and lengthwise of the latter, said unit consisting of a block and a cutter mounted on the block, a screw shaft in and extending lengthwise of the guideway in screwthreaded relation to the block, to cause the block to move along the guideway when the shaft is turned, an upwardly projecting pin on said expansible means movable with the latter to cause the pin to lie at the same distance from the wall of any cylinder in which said device is mounted, and a star wheel on the lower end of the shaft in position to engage said pin and cause the shaft to turn step by step as th 'rotatable member is turned.

HERBERT A. BERKMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

